Low-head vertical-shaft hydro-electric set



July 28, 1959 c. M. FEVRE LOW-HEAD VERTICAL-SHAFT HYDRO-ELECTRIC SETFiled Nov. 25, 1956 I v I INVENTOR Ii'% CHARLES MARIE FEVRE BY W, *Mw

A TTORME YS United States Patent LOW-HEAD VERTICAL-SHAFT HYDRO-ELECTRICS'ET Charles Marie Fevre, Le Creusot, France, assignor to Socit desForges et Ateliers du Creusot, Paris, France, a French companyApplication November 23, 1956, Serial No. 623,960 Claims priority,application France November 30, 1955 3 Claims. (Cl. 290-52) The presentinvention relates to a new arrangement intended to reduce thediametrical dimensions of the spiral chamber in low-head vertical-shafthydro-electric sets, which allows an appreciable reduction in civilengineering works, and consequently in the cost of installation.

It is known that the water passage cross-sections at each point of thespiral chamber are calculated as a function of the delivery and of thehead available; the dimensions of the spiral chamber are thus determinedon the one hand by the passage cross-sections to be provided, and on theother hand by the diameter about which the spiral chamber is developed.

According to the invention, the spiral chamber is developed about acentral lining of which the maximum diameter is substantially equal tothat of the moving wheel, the lower part of the lining being of asubstantially truncated conical shape connected to the hub of the saidwheel in such a way as to form the central core of the annular outletduct of the spiral chamber, the said lining, which consists of ametallic caisson which may support the pivot of the unit, itself beingsupported at the inlet of the said duct by way of inclined pro-guidingblades, the blades of the distributor being articulated about axesinclined along a direction substantially normal to the truncated conicalprofile of the lining.

Two particular forms of embodiment of a hydroelectric set according tothe invention are illustrated more or less diagrammatically in theattached drawing, and are described hereinafter by way of examples.

In the drawing: a

Figure 1 is a vertical section through a set having a Kaplan turbine inwhich the alternator is situated above the metallic caisson.

Figure 2 is a vertical section through a set in which the alternator issituated inside the metallic caisson.

In these figures, 1 designates the turbine wheel mounted below a spiralchamber 2, which is accommodated in the concrete mass 3 of the station,and communicates directly with the upstream water level 4.

A metallic caisson 5 fitted in the concrete girder 6 is situated at thecentre of the spiral chamber 2, ofwhich the said concrete girder formsthe ceiling; this caisson is supported on the foundations by way of thecasing 7 of the turbine, by means of the girders 8 which form the fixedpreguiding blades.

The upper part of the caisson 5 is cylindrical, while the lower part 9is contoured in such a manner as to be connected to the hub of thewheel, and to form the central core of an annular duct 10 of which theexternal wall is formed by the casing 7.

The blades 11 of the distributor are situated about this casing 7, andare articulated about axes substantially perpendicular to the centralcore of the said annular duct 10 in such a manner as to form a conicaldistributor of small diameter.

The lower part 9 of the caisson 5 carries the lower guide bearing 12 ofthe shaft 13 of the group.

In the embodiment illustrated in Figure 1, the pivot 14 of the set whichmay be any suitable type of combined radial and thrust bearing issituated inside the caisson 5, with the fixed part 19 thereof bearing ona solid horizontal shoulder 19 of the caisson 5 to support wheel 1 induct 10. The alternator consisting of the stator 16 and the rotor 17 issituated above the girder 6, which absorbs the reaction of theelectrical torque of the alternator.

According to the embodiment illustrated in Figure 2, the stator 16 ofthe alternator is situated inside the caisson 5, while the pivot 14 issituated at the top of caisson 5.

This arrangement lends itself particularly well to installation in astation of the pier type; in fact, it allows the plan measurements ofeach set to be reduced, and the feed of water from the inlet chamber tothe turbine to be improved.

It must be understood that the set can be modified, or completed by anyuseful accessories, without departing from the scope of the invention.

Furthermore, the invention is not limited to turbines of the type shownand is applicable to turbines which include mechanism {or orienting thevanes and to turbines having a Francis wheel which is used with aconical distributor.

What I claim is:

1. In a low-head vertical-shaft hydro-electric set including a turbinewheel having a hub, a spiral chamber, an annular outlet duct for saidchamber, a cylindrical metal caisson forming a central lining for saidchamber and having a diameter substantially equal to the diameter ofsaid wheel, a truncated conical portion of said caisson forming acentral core for said outlet duct and fairing into the hub of saidwheel, inclined pre-guiding blades supporting said caisson in saidchamber and distributor blades articulated about their long axis andsubstantially normal to the profile of said truncated conical portion,said wheel being mounted in said outlet duct.

2. A hydro-electric set as described in claim 1 in which said caissonsupports the set when said wheel is in position in said duct.

3. A hydro-electric set as described in claim 1 includ ing a generatorhaving a stator and a rotor, said stator being centered within saidcaisson.

References Cited in the file of this patent UNITED STATES PATENTS

